1. Field of the Invention
The present invention relates to an input device that outputs an operation signal to operate an electric device, for example, a car-mounted electric device by rotating an operating member manually. More specifically, it relates to a force-feedback input device that gives a predetermined dynamic sensation, that is to say, a force-feedback from an operating member to an operator by applying an external force to the operating member according to a rotation angle thereof.
2. Description of the Related Art
There is known a force-feedback input device including a case; a rotatable operating member, for example, a knob accommodated in the case; a rotary encoder detecting a rotation angle of the knob; an external force applier, for example, a motor applying external force to the knob; and a controller outputting an operation signal to an object of operation and controlling a driving force of the motor, according to the rotation angle of the knob detected by the rotary encoder. This is described in, for example, Japanese Unexamined Patent Application Publication No. 2003-50639.
This force-feedback input device is an input device that outputs an operation signal to operate an electric device, for example, a car-mounted electric device by rotating an operating member manually. The objects of operation are, for example, air flow control and air outlet selection of a car-mounted air conditioner, volume control and tuning of a radio, and volume and tone control of an audio system.
For example, in the case of air flow control of a car-mounted air conditioner, when a knob is rotated in the direction of increasing the air flow, a motor provides the knob with the torque in the opposite direction. The counter torque increases with the increase of the rotation angle of the knob. Through the sensation of resistance (force-feedback) accompanying the increase of the resistance force applied by the knob, an operator can know the rotated angle of the knob in the direction of increasing the air flow.
Besides the above-mentioned force-feedback input device giving the sensation of resistance as force-feedback, there is a force-feedback input device giving the sensation of acceleration as force-feedback by providing the knob with the torque in the same direction as the rotation of the knob. In addition, there is a force-feedback input device giving a clicking sensation as force-feedback by reversing the direction of the torque provided for the knob when the rotation angle of the knob exceeds a predetermined angle.
The force-feedback input device is desired to be reduced in thickness. However, since the force-feedback input device has the structure in which a knob, a rotary encoder, and a motor are disposed in the direction of the shaft of the knob, the size in the direction of the shaft is inevitably great and the reduction in thickness cannot be achieved.